Section 7 GMC SIERRA 2010 Repair Manual

If No Steam Is Coming From The
Engine Compartment
The ENGINE OVERHEATED STOP ENGINE or the
ENGINE OVERHEATED IDLE ENGINE message, along
with a low coolant condition, can indicate a serious
problem.
If you get an engine overheat warning, but see or hear
no steam, the problem may not be too serious.
Sometimes the engine can get a little too hot when you:
.Climb a long hill on a hot day.
.Stop after high-speed driving.
.Idle for long periods in traffic.
.Tow a trailer. SeeTowing a Trailer on page 5‑50.
If you get the ENGINE OVERHEATED STOP ENGINE
or the ENGINE OVERHEATED IDLE ENGINE message
with no sign of steam, try this for a minute or so: 1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest fan speed. Open the windows as
necessary.
3. If you are stopped in a traffic jam, apply the brake, shift to N (Neutral); otherwise, shift to the highest
gear while driving —D (Drive) or 3 (Third). If the temperature overheat gage is no longer in the
overheat zone or an overheat warning no longer
displays, the vehicle can be driven. Continue to drive
the vehicle slow for about 10 minutes. Keep a safe
vehicle distance from the car in front of you. If the
warning does not come back on, continue to drive
normally.
If the warning continues, pull over, stop, and park the
vehicle right away.
If there is no sign of steam, idle the engine for
five minutes while parked. If the warning is still
displayed, turn off the engine until it cools down. Also,
see
“Overheated Engine Protection Operating Mode”
later in this section.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternates firing groups
of cylinders helps prevent engine damage. In this mode,
you will notice a loss in power and engine performance.
This operating mode allows the vehicle to be driven to a
safe place in an emergency. Driving extended
miles (km) and/or towing a trailer in the overheat
protection mode should be avoided.
6-36

Do not top off the brake fluid. Adding fluid does not
correct a leak. If fluid is added when the linings are
worn, there will be too much fluid when new brake
linings are installed. Add or remove brake fluid, as
necessary, only when work is done on the brake
hydraulic system.
{WARNING:
If too much brake fluid is added, it can spill on the
engine and burn, if the engine is hot enough. You
or others could be burned, and the vehicle could
be damaged. Add brake fluid only when work is
done on the brake hydraulic system. See
“Checking Brake Fluid”in this section.
Refer to the Maintenance Schedule to determine when
to check the brake fluid. See Scheduled Maintenance
on page 7‑3.
Checking Brake Fluid
Check brake fluid by looking at the brake fluid reservoir.
SeeEngine Compartment Overview on page 6‑16.
The fluid level should be
above MIN. If it is not,
have the brake hydraulic
system checked to see if
there is a leak.
After work is done on the brake hydraulic system, make
sure the level is above the MIN but not over the
MAX mark.
What to Add
Use only new DOT 3 brake fluid from a sealed
container. See Recommended Fluids and Lubricantson
page 7‑12.
Always clean the brake fluid reservoir cap and the area
around the cap before removing it. This helps keep dirt
from entering the reservoir.
6-40

.For all 6.0L and 6.2L 2500HD Series applications,
the proper level is from 0 to 0.5 inches (0 mm to
13 mm) below the bottom of the filler plug hole,
located on the rear axle. Add only enough fluid to
reach the proper level.
.For all 6.6L DURAMAX DIESEL 2500HD Series
applications and all 3500 Series applications, the
proper level is from 0.6 inches to 0.8 inches
(17 mm to 21 mm) below the bottom of the filler
plug hole, located on the rear axle. Add only
enough fluid to reach the proper level.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. SeeRecommended Fluids and
Lubricants on page 7‑12.
Four-Wheel Drive
Lubricant checks in this section also apply to these
vehicles.
Transfer Case
When to Check Lubricant
It is not necessary to regularly check transfer case fluid
unless you suspect there is a leak, or you hear an
unusual noise. A fluid loss could indicate a problem.
Have it inspected and repaired.
How to Check Lubricant
Electric Shift Transfer Case
A. Fill Plug
B. Drain Plug
6-50

9. Make sure that the light from the headlamp ispositioned at the bottom edge of the horizontal
tape line. The lamp on the left (A) shows the
correct headlamp aim. The lamp on the right (B)
shows the incorrect headlamp aim.
10. Repeat Steps 7 through 9 for the opposite headlamp.
Bulb Replacement
For the proper type of replacement bulbs, see
Replacement Bulbs on page 6‑62.
For any bulb changing procedure not listed in this
section, contact your dealer/retailer.
Halogen Bulbs
{WARNING:
Halogen bulbs have pressurized gas inside and
can burst if you drop or scratch the bulb. You or
others could be injured. Be sure to read and
follow the instructions on the bulb package.
Headlamps
To replace one of these bulbs:
1. Open the hood. See Hood Release
on page 6‑15for more information.
2. If you are replacing the bulb on the passenger side remove the Engine Air Cleaner cover. See Engine
Air Cleaner/Filter
on page 6‑21for more
information.
3. Reach in and access the bulb sockets from inside the engine compartment.
6-57

Notice:If the vehicle has low‐profile tires, they
are more susceptible to damage from road
hazards or curb impact than standard profile
tires. Tire and/or wheel assembly damage can
occur when coming into contact with road
hazards like, potholes, or sharp edged objects,
or when sliding into a curb. The vehicle
warranty does not cover this type of damage.
Keep tires set to the correct inflation pressure
and, when possible avoid contact with curbs,
potholes, and other road hazards.
Tire Sidewall Labeling
Useful information about a tire is molded into the
sidewall. The following illustrations are examples
of a typical P‐Metric and a LT‐Metric tire sidewall.
Passenger (P‐Metric) Tire
(A) Tire Size:The tire size code is a combination
of letters and numbers used to define a particular
tire's width, height, aspect ratio, construction type,
and service description. See the “Tire Size”
illustration later in this section for more detail.
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Light Truck (LT-Metric) Tire
(A) Tire Size:The tire size code is a combination
of letters and numbers used to define a particular
tire's width, height, aspect ratio, construction type,
and service description. See the “Tire Size”
illustration later in this section for more detail. (B) TPC Spec (Tire Performance Criteria
Specification)
:Original equipment tires designed
to GM's specific tire performance criteria have a
TPC specification code molded onto the sidewall.
GM's TPC specifications meet or exceed all
federal safety guidelines.
(C) Dual Tire Maximum Load
:Maximum load
that can be carried and the maximum pressure
needed to support that load when used in a dual
configuration. For information on recommended
tire pressure see Inflation - Tire Pressure
on
page 6‑72
and Loading the Vehicleon page 5‑30.
(D) DOT (Department of Transportation)
:
The Department of Transportation (DOT) code
indicates that the tire is in compliance with the
U.S. Department of Transportation Motor Vehicle
Safety Standards.
(E) Tire Identification Number (TIN)
:The letters
and numbers following DOT code are the Tire
Identification Number (TIN). The TIN shows the
manufacturer and plant code, tire size, and date
the tire was manufactured. The TIN is molded
onto both sides of the tire, although only one side
may have the date of manufacture.
6-67

(F) Tire Ply Material:The type of cord and
number of plies in the sidewall and under the
tread.
(G) Single Tire Maximum Load
:Maximum load
that can be carried and the maximum pressure
needed to support that load when used as a
single. For information on recommended tire
pressure see Inflation - Tire Pressure
on page 6‑72
andLoading the Vehicleon page 5‑30.
Tire Size
The following examples show the different parts of
a tire size.
Passenger (P‐Metric) Tire
(A) Passenger (P‐Metric) Tire:The United
States version of a metric tire sizing system. The
letter P as the first character in the tire size means
a passenger vehicle tire engineered to standards
set by the U.S. Tire and Rim Association. (B) Tire Width
:The three‐digit number indicates
the tire section width in millimeters from sidewall
to sidewall.
(C) Aspect Ratio
:A two‐digit number that
indicates the tire height‐to‐width measurements.
For example, if the tire size aspect ratio is 75, as
shown in item C of the tire illustration, it would
mean that the tire's sidewall is 75 percent as high
as it is wide.
(D) Construction Code
:A letter code is used to
indicate the type of ply construction in the tire.
The letter R means radial ply construction; the
letter D means diagonal or bias ply construction;
and the letter B means belted‐bias ply
construction.
(E) Rim Diameter
:Diameter of the wheel
in inches.
(F) Service Description
:These characters
represent the load index and speed rating of the
tire. The load index represents the load carry
capacity a tire is certified to carry. The speed
rating is the maximum speed a tire is certified to
carry a load.
6-68

Light Truck (LT‐Metric) Tire
(A) Light Truck (LT‐Metric) Tire:The United
States version of a metric tire sizing system.
The letters LT as the first two characters in the
tire size means a light truck tire engineered to
standards set by the U.S. Tire and Rim
Association.
(B) Tire Width
:The three‐digit number indicates
the tire section width in millimeters from sidewall
to sidewall.
(C) Aspect Ratio
:A two‐digit number that
indicates the tire height‐to‐width measurements.
For example, if the tire size aspect ratio is 75, as
shown in item C of the light truck (LT‐Metric) tire
illustration, it would mean that the tire's sidewall is
75 percent as high as it is wide. (D) Construction Code
:A letter code is used to
indicate the type of ply construction in the tire.
The letter R means radial ply construction; the
letter D means diagonal or bias ply construction;
and the letter B means belted‐bias ply
construction.
(E) Rim Diameter
:Diameter of the wheel in
inches.
(F) Load Range
:Load Range.
(G) Service Description
:The service description
indicates the load index and speed rating of
a tire. If two numbers are given as in the example,
120/116, then this represents the load index for
single versus dual wheel usage (single/dual).
The speed rating is the maximum speed a tire is
certified to carry a load.
6-69

The low tire pressure warning light may come on in cool
weather when the vehicle is first started, and then turn
off as you start to drive. This could be an early indicator
that the air pressure in the tire(s) are getting low and
need to be inflated to the proper pressure.
A Tire and Loading Information label, attached to your
vehicle, shows the size of your vehicle's original
equipment tires and the correct inflation pressure for
your vehicle's tires when they are cold. SeeLoading the
Vehicle
on page 5‑30, for an example of the Tire and
Loading Information label and its location on your
vehicle. Also see Inflation - Tire Pressure on page 6‑72.
Your vehicle's TPMS can warn you about a low tire
pressure condition but it does not replace normal tire
maintenance. See Tire Inspection and Rotation
on
page 6‑80and Tires on page 6‑64.
Notice: Liquid tire sealants could damage the Tire
Pressure Monitor System (TPMS) sensors. Sensor
damage caused by using a tire sealant is not
covered by your warranty. Do not use liquid tire
sealants.
TPMS Malfunction Light and Message
The TPMS will not function properly if one or more of
the TPMS sensors are missing or inoperable. When the
system detects a malfunction, the low tire warning light
flashes for about one minute and then stays on for the
remainder of the ignition cycle. A DIC warning message
is also displayed. The low tire warning light and DIC
warning message come on at each ignition cycle until
the problem is corrected. Some of the conditions that
can cause the malfunction light and DIC message to
come on are:
.One of the road tires has been replaced with the
spare tire. The spare tire does not have a TPMS
sensor. The TPMS malfunction light and DIC
message should go off once you re‐install the road
tire containing the TPMS sensor.
.The TPMS sensor matching process was started
but not completed or not completed successfully
after rotating the vehicle's tires. The DIC message
and TPMS malfunction light should go off once the
TPMS sensor matching process is performed
successfully. See “TPMS Sensor Matching
Process” later in this section.
6-77

Different Size Tires and Wheels
If you add wheels or tires that are a different size than
your original equipment wheels and tires, this could
affect the way your vehicle performs, including its
braking, ride and handling characteristics, stability, and
resistance to rollover. Additionally, if your vehicle has
electronic systems such as anti‐lock brakes, rollover
airbags, traction control, and electronic stability control,
the performance of these systems can be affected.
{WARNING:
If you add different sized wheels, your vehicle
may not provide an acceptable level of
performance and safety if tires not recommended
for those wheels are selected. You may increase
the chance that you will crash and suffer serious
injury. Only use GM specific wheel and tire
systems developed for your vehicle, and have
them properly installed by a GM certified
technician.
See Buying New Tires
on page 6‑83andAccessories
and Modificationson page 6‑4for additional
information.
Uniform Tire Quality Grading
Quality grades can be found where applicable on
the tire sidewall between tread shoulder and
maximum section width. For example:
Treadwear 200 Traction AA
Temperature A
The following information relates to the system
developed by the United States National
Highway Traffic Safety Administration (NHTSA),
which grades tires by treadwear, traction, and
temperature performance. This applies only to
vehicles sold in the United States. The grades are
molded on the sidewalls of most passenger car
tires. The Uniform Tire Quality Grading (UTQG)
system does not apply to deep tread, winter-type
snow tires, space-saver, or temporary use
spare tires, tires with nominal rim diameters of
10 to 12 inches (25 to 30 cm), or to some
limited-production tires.
6-85